1. Field of the Invention
The present invention relates to a process for producing an ink-jet printer member. More particularly, the present invention pertains to a process for efficiently producing an ink-jet printer member which comprises a plastics substrate and an elastic material layer that are integrally composited by means of multi-color injection molding or insert molding.
2. Description of the Related Arts
An ink-jet printer has heretofore been equipped with an ink tank which has an ink chamber to be filled in with an ink and an ink supply portion that supplies a recording head portion with an ink. Examples of types of the ink tanks include a type which is constituted so that an ink is supplied to a recording head which is stationarily attached to a carriage, through tubes arranged everywhere in an ink-jet printer, and an ink tank is freely attachable to and detachable from said priter; a type in which an ink tank is constituted integrally with a recording head, and the resultant integrated unit is freely attachable to and detachable from a carriage; and the like types.
In the former type of the tank, an ink is supplied to the recording head by providing a water head difference therebetween, while in the latter type, an ink is supplied to the recording head by providing the ink tank with a negative pressure generation source.
There have frequently been proposed in recent years, the ink-jet printers which adopt the latter type of the ink tank from the viewpoints of miniaturizing the printer as well as the easiness of maintenance work.
Such an ink tank is required to be capable of favorably supplying an ink in an amount corresponding to the amount of the ink discharged from the recording head at the time of recording, and also to be free from the leakage of an ink through a discharge port at the time of non-recording.
There is available for example, as an ink tank meeting the above-mentioned requirements, an ink tank in the form of cartridge in which a recording head is integrated with an ink tank, and an absorbent (foam) is filled inside the ink tank. It is made possible by such absorbent filled in an ink tank to maintain the ink meniscus at an stable level at the ink discharge portion of the recording head, and at the same time it is made possible by the capillary power of the absorbent to properly preserve the ink in the ink tank. In this case, it is needed that almost entire inside of the ink tank be filled in with the absorbent. Thus by allowing the absorbent to preserve an amount of ink a slightly less than the maximum preservable amount thereof, the capillary power of the absorbent is utilized to generate a negative internal pressure. It is therefore, made possible to minimize the amount of the ink leaking through the discharge portion of the recording head and through the ink tank portion communicating with the atmosphere, even in the case where a mechanical shock such as vibration or a thermal shock such as temperature variation is applied to the recording head or the ink tank.
The aforesaid method in which the ink tank inside is almost entirely filled with an absorbent involves the problems that the negative pressure of the absorbent increases accompanying the consumption of the ink, and increases the amount of the ink remaining in the ink tank without being supplied to the recording head, thereby bringing about a low utilization efficiency of the ink.
In order to solve such problems, an attempt is made, for example, to employ an ink tank valve which is installed at the position dividing an ink chamber and an ink supply portion, and which supplies a recording head with the ink that is moved by the difference in pressure between the ink chamber and the ink supply portion, and is filled in the ink chamber [refer to Japanese Patent Application Laid-Open No.174860/1996(Hei-8)].
By equipping the ink tank with such an ink tank valve, it is made possible to certainly supply the recording head with the ink, by surely responding to the slight difference in pressure between the ink tank and the recording head without being influenced by the swing of the ink due to the movement of the carriage, while maintaining the negative pressure well suited for printing between the recording head and a recording medium. It is further made possible thereby to prevent the ink from leaking by variation in temperature through the ink supply port or through the recording head.
There is usually used in the ink tank valve, an elastic material, for example a plastics substrate to which an elastic material is adhesively bonded. In the case of producing such a member comprising a plastics substrate and an elastic material adhesively bonded thereto, there has heretofore been adopted a method in which the plastics substrate and the elastic material are each separately produced by molding, and thereafter they are adhesively bonded to each other. The above-mentioned method, however, suffers from the disadvantages of increased number of production steps, complicated operations and a high production cost.
The ink supply port is provided with a sealing member for preventing ink from leaking. Such a sealing member has heretofore been installed by (1) a method in which an adhesive is applied to a plastics memeber, and then is molded into the form of a sealing member by pressing the same with a metal plate from the upside, (2) a method in which a plastics memeber prepared in advance is equipped with an o-ring made of thermosetting rubber, or a sealing member of a prescribed shape which is blanked from thermosetting rubber in the form of a flat plate or the like, or a sealing member of a prescribed shape which is injection-molded from thermosetting rubber.
Nevertheless the above-mentioned (1) adhesive coating method involves the problems of control of adhesives being troublesome, post-treatment being needed for squeezed out adhesives and the like troubles On the other hand, the (2) sealing member-equipping method involves the problems of increased number of processing steps due to the necessity of forming in advance a sealing member of a prescribed shape, and an inevitably high production cost and the like.